The present invention concerns a push button device for a timepiece used, for example, to start a chronograph in the pushed in position, and allowing time data or a date to be corrected in a pulled out position.
A timesetting device for an electronic watch including a push button having a shape such that it allows the device to he actuated by a user is known from Swiss Patent No. 577 701. The push button comprises a pusher head which is driven onto a pusher stem and held thereon said stem allowing a timesetting device to be actuated. Inside the pusher head is arranged a recess of generally cylindrical shape in which is disposed a return spring which bias the pusher head axially towards an initial rest position. The pusher stem carries a crown which, when the user presses on the pusher head, engages in a recess of a timesetting element attached to the movement of the watch. This element allows high frequency pulses to be supplied to the hour and minute indicators driving means of the watch. The sole function of the push button device disclosed in this Patent is to allow timesetting. Further, it applies to an electronic watch.
Swiss Patent No. 506 115 also discloses a time correcting device for a watch whose pinion and timesetting stem have an axis of rotation perpendicular to the plane of the watch movement, which rules out a chronograph function since the user is obliged to act on the pinion via the back face of the watch case. Moreover, the indexing function of the timesetting stem is defined by a spring attached to the case and co-operating with said stem.
Further, Swiss Patent No. 3647 discloses a timesetting mechanism for a watch including a timesetting pinion, a winding pinion and a timesetting stem. The timesetting stem is provided with a square section via which it engages the winding pinion when it is in the pushed in position, and the timesetting pinion when it is in the pulled out position. This is not a push button device, but a simple timesetting stem with two coaxial pinions.